Anti-platelet drug: Anti-platelet drug is a medication which inhibits the function of blood cells which help in blood clotting known as platelets. Anti platelet drugs are widely used in the treatment of heart attack, stroke and other disorders due to enhanced clotting of blood within the blood vessels.
Anti-platelet medications in regular use are as follows:
Most commonly used anti-platelet drug is aspirin. Aspirin was initially used a pain killer and for treatment of fever. It was discovered more than a century back. Dose used for anti-platelet action is much lower compared to that needed for its pain killer action. Irritation of the lining of the stomach (gastritis) is an important side effect which limits the use of aspirin. For preventing this problem, special preparations with a coating so that the drug will be released only in the intestine (enteric coated aspirin) are used. Being an old drug, aspirin is quite inexpensive.
Clopidogrel is another commonly used anti-platelet medication. It has less chance of irritating the inner lining of the stomach and is usually better tolerated by patients. In high risk cases, clopidogrel is often combined with aspirin. This is the case with a recent heart attack, persons who have an implanted stent (small mesh like tube in blood vessels) or after a recent coronary artery bypass operation. Being a newer medication it costlier than aspirin.
Ticagrelor is one of the latest anti platelet medications. Of course it is much more expensive than the former two described above. It is also more effective than the other two. Hence its use is mostly restricted to high risk cases. It is also combined with aspirin to give dual anti-platelet treatment, which is obviously more effective than a single agent. But combining two medications also increases the potential risk of bleeding episodes.
An older medication which is not being used is ticlopidine. Yet another one is prasugrel, which is also used less frequently.
Risks of anti-platelet medications
Most important risk is an extension of its beneficial action, that is bleeding episodes due to excessive anti clotting action. Often the bleeding manifestations are minor, though rarely severe episodes can occur, mostly when there is an injury or another disease which increases the chance of bleeding. Any of the anti-platelet medication can produce allergic manifestations in susceptible persons. Irritation of the inner lining of the stomach is usually seen with aspirin. It can often be tided over by special ‘enteric coating’ or using medications to protect the stomach in addition.
What to do in case of bleeding?
Immediate first aid is to apply local pressure over the bleeding site and bandage if possible. Cautious application of ice may also be useful. In case of any severe bleed, immediate medical attention is mandatory. Further doses of the medication may have to be temporarily withheld depending on the severity of the bleeding and the nature of the original disease for which it was started.
Stopping of anti-platelet medications prior to planned operations
It may be necessary to stop anti-platelet medications prior to planned surgery (operations) in order to reduce the chance of bleeding. This should be done in consultation with the doctor who has prescribed the medication, considering the reason for giving the medications. For most major procedures, these drugs may have to be stopped 5 days prior. But in case of emergencies, it may not be possible. Then extra precautions have to be taken to reduce the chance of bleeding. There is always a risk of worsening of the original disease while stopping the medication.